Tank with floating roof



Se t. 8, 1953 F. o. MJELLEM TANK WITH FLOATING ROOF INVENTOR.

Maw

Filed Aug. 24, 1951 Patented Sept. 8, 1953 UNITED STATES PATENT orrics TANK WITH FLOATING ROOF Frantz 0. 'Mjellem, Alhambra, Califi, assignor to American Pipe & Steel Corporation, Alhambra, Calif., a corporation of Nevada Application August 24, 1951, Serial No. 243,409

3 Claims. 1

This invention relates to a floating roof tank.

In the storage of volatile fluids, tanks have heretofore been designed which employ floating roofs or pontoons which float on the stored liquid in the tank. A plurality of shoes or metal plates surround the floating roof or pontoon and are pressed outwardly against the inner faces of the tank walls. A flexible seal is normally provided between the shoes and the floating roof tending to confine volatile fluids and prevent the ingress of outside substances.

Heretofore, suitable connections have been provided between the sides of the floating roof and the shoes so that when the liquid level in the tank rises or falls excessively, the shoes will be raised or lowered by these connections so as to be disposed opposite the edges of the roof. Usually, such connections have heretofore been located in the space between the edges of the roof and the shoes and as this space is relatively small such connections are relatively inaccessible, making it diflicult to assemble the structure of the tank and also difiicult to make inspections and repairs.

A primary object of the present invention is to provide an improved floating roof tank wherein the connections between the floating roof and the shoes are so designed as to be readily accessible, thus facilitating the assembly of the elements of the tank and facilitating inspection and repair.

Another object of the invention is to provide a floating roof tank wherein the elements connecting the shoes with the floating roof are of relatively simple and durable construction and which will tend to maintain the floating roof centrally of the tank.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawing for an illustrative embodiment of the invention, wherein:

Figure 1 is a partial view in vertical section, illustrating one form of floating roof tank embodying the present invention;

Fig. 2 is a partial view in horizontal section taken substantially upon the line 2-2 upon Fig. 1; and

Fig. 3 is a view similar to Fig. 1, but illustrating a slightly modified form of construction.

Referring to the accompanying drawing Wherein similar reference characters designate similar parts throughout, l0 indicates generally a storage tank having a bottom H and walls [2.

Within the tank there is a floating roof generally indicated at l3 having a top I4, a bottom l5, and side walls IS. The floating roof occupies the major portion of the horizontal cross-sec tional area of the tank so that in conformity with conventional practice the space between the side walls I6 and the walls I2 is relatively small. Shoes or plates I! are disposed within the tank around the floating roof [3, These plates or shoes are arcuate in form as shown in Fig. 2 and have top and bottom edges bent inwardly as indicated at I8 and I9.

On the exterior of the walls Hi there are a plurality of pockets attached thereto, such as by welding. Some of these pockets, such as those illustrated at 20, are upwardly open and others are downwardly open as indicated at 2|. Leaf springs 22 are provided which are bolted or otherwise detachably secured to the inwardly bent portions l8 of the shoes l1. These springs extend downwardly into the upwardly open pockets 20. In a similar manner, leaf springs 23 are bolted or otherwise detachably secured to the inwardly 'bent portions l9 and extend upwardly into the downwardly open pockets 2|. The arrangement is such that there is some clearance between the ends of the springs 22 and 23 and the backs or bottoms of their respective pockets so that small vertical fluctuations of the floating roof l3 do not stress or disturb either set of springs. However, if the roof 13 should rise severely due to a rise of the liquid level in the tank the bottoms of the pockets 20 will engage the bottoms of the springs 22 and the shoes I! will be bodily shifted upwardly with respect to the tank walls 12. Conversely, if the roof l3 descends severely the backs or bottoms of the pockets 2| will engage the springs 23 and shift the shoes I downwardly. A flexible sealing strip 24 loosely connects the portions I8 of the shoes with the top of the floating roof l3. This sealing strip may be formed of any flexible or impervious material and serves to confine volatile vapors to some extent and to prevent ready ingress of outside substances, such as rain water and the like.

As will be observed from Fig. 1, the vertical height of the shoes I! is greater than the vertical height of the floating roof l3. Consequently, the points at which the springs 22 are attached to the shoe H are Well above the limited space between the roof l3 and the tank wall 12. The bolts used to attach the springs are consequently readily accessible. In a similar manner the bolts used to attach the springs 23 are readily u accessible as these are located below the bottom of the roof. This arrangement greatly facilitates the assembly of the parts of the floating roof tank when the tank is originally installed and also facilitates inspection and repair as contrasted with other constructions wherein the connections between the floating roof and the shoes are limited directly between the walls I6 and the shoes H.

In Fig. 3, an alternative form of construction is disclosed wherein in addition to the structure above described the roof 130. also is equipped with ears 25 at suitable intervals through which cranks 26 extend. These cranks have upwardly and downwardly directed arms, the ends of which are slidably disposed in slots '21 formed in short ribs 28 that are welded or otherwise secured to the shoes Ila. The slots 21 afford a limited relative movement of the roof with respect to the shoes, but when the movement becomes excessive ends of the slots are encountered by the ends of the cranks causing the shoes to be bodily shifted sympathetically with the moveme'nts of the roof.

From the above-described constructions it will be appreciated that a relatively simple yet highly durable floating roof tank is provided which is highly advantageous in that the parts connecting the floating roof to the shoes are so arranged as to be readily accessible. The springs 22 and 23 also cooperate to maintain the roof centrally with relation to the tank.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In a liquid storage tank having a floating roof, shoes engageable with the inside faces of the walls of the tank, upwardly open pockets on the sides of the floating roof, downwardly open pockets on the sides of the roof, leaf springs secured to the shoes extending downwardly into the upwardly, open pockets and leaf springs secured to the shoes extending upwardly into the downwardly open pockets, the spacing between the ends of the springs being greater than the spacing between the backs of the pockets whereby the roof may have a limited free movement independent of the shoes but when movements of the roof are great, the leaf springs will be engaged by the backs of the pockets causing the 4 shoes to be shifted sympathetically with the roof relatively to the tank walls.

2. In a liquid storage tank having a floating roof, shoes engageable with the inside faces of the walls of the tank, upwardly open pockets on the sides of the floating roof, downwardly open pockets on the sides of the roof, leaf springs secured to the shoes extending downwardly into the upwardly open pockets and leaf springs secured to the shoes extending upwardly into the downwardly open pockets, the spacing between the ends of the springs being greater than the spacing between the backs of the pockets whereb the roof may have a limited free movement independent of the shoes but when movements of the roof are great, the leaf springs will be engaged by the backs of the pockets causing the shoes to be shifted sympathetically with the roof relatively to the tank walls, and cranks pivotally mounted on the roof having pin and slot connections with the shoes.

3. In a liquid storage tank having a floating roof, shoes engageable with the inside faces of the walls of the tank, upwardly open pockets on the sides of the floating roof, downwardly open pockets on the sides of the roof, leaf springs secured to the shoes extending downwardly into the upwardly open pockets and leaf springs secured to the shoes extending upwardly into the downwardly open pockets, the spacing between the ends of the springs being greater than the spacing between the backs of the pockets where- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,900,904 Berger Mar. 14, 1933 1,930,953 Hampton Oct. 17, 1933 1,992,221 Kramer Feb. 26, 1935 2,148,811 Grifiin Feb. 28, 1939 2,478,422 Plummer Aug. 9, 1949 

